All Non-Fermi sirens in the County of Monroe, upgraded to current digital technology in 2006, are given a preventative maintenance check-up annually. Some quick facts about the siren system:
The current sirens were the original sirens installed 1982 by Detroit Edison for warning of a Fermi incident.
The sirens are a combination of Whelen WS-2000 and WS-3000 units. The sirens are electronic, and are capable of 5 different siren tones plus public address.
The sirens were installed in the current location in 2001-2002, and have served the community well for the past few years.
The sirens are a "one-way" system - meaning, that a signal is sent out to the sirens via radio from the Emergency Operations Center or Monroe County Central Dispatch, the siren activates, and no feedback is received on siren activation.
Parts are getting difficult to find, as these models have been obsolete for a number of years. At this time, several units are out of service due to lack of parts availability.
Digital 2-way Upgrade:
The upgrade involved removing the control cabinets from the siren poles and installing the Federal Signal Ultravoicedigital control system. The siren heads shown above remained the same. Activation equipment now transmits a command to the control system, performs the requested function, and then returns the status of activation to the siren. This system can also be silent tested, fully exercising the system without making any audible sound.
OR Sends signal to Ultravoice Control
Which in turn, actives the siren and sends a signal back to the activation point to verify function.
In conjunction with the siren upgrade, several jurisdictions added additional sirens. Because the Whelen units that are installed throughout the county are obsolete, and the activation and control equipment is manufactured by Federal Signal, the Modulator model 6024 was utilized.
Before the upgrade to digital, the siren system depended on an operator broadcasting a voice message live via the radio system. When a voice message is broadcast, the output of the siren decreases to compensate for the variations in voices.
Digital voice chips were installed in each of the Ultravoice controllers on the poles, and have been optimized to bring the voice up to the same output level as the sirens. Digital voice messages were then recorded and placed in the siren equipment.